简介
THREE.TubeGeometry可以沿着一条三维的样式曲线（THREE.CatmullRomCurve3对象）拉伸出一根管。
最简单实现
var tubeGeometry = new THREE.TubeGeometry(path,segments,radius,radiusSegments,closed);相关参数说明
| 属性 | 是否必需 | 描述 |
|---|---|---|
| path | 是 | 该属性用一个THREE.CatmullRomCurve3对象来指定THREE.TubeGeometry对象应当遵循的路径 |
| segments | 否 | 该属性指定构建这个THREE.TubeGeometry对象所用的分段数。默认值为64。路径越长，指定的分段数应该越多 |
| radius | 否 | 该属性指定THREE.TubeGeometry对象的半径。默认值为1 |
| radiusSegments | 否 | 该属性指定THREE.TubeGeometry对象圆周的分段数。默认值为8。分段数越多，越圆滑 |
| colosed | 否 | 如果该属性设为true，THREE.TubeGeometry头和尾部会连接起来。默认值为false。 |
案例代码
案例查看地址：http://www.wjceo.com/blog/threejs/2018-02-12/47.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style type="text/css"> html, body { margin: 0; height: 100%; } canvas { display: block; } </style>
</head>
<body onload="draw();">
</body>
<script src="https://johnson2heng.github.io/three.js-demo/lib/three.js"></script>
<script src="https://johnson2heng.github.io/three.js-demo/lib/js/QuickHull.js"></script>
<script src="https://johnson2heng.github.io/three.js-demo/lib/js/geometries/ConvexGeometry.js"></script>
<script src="https://johnson2heng.github.io/three.js-demo/lib/js/controls/OrbitControls.js"></script>
<script src="https://johnson2heng.github.io/three.js-demo/lib/js/libs/stats.min.js"></script>
<script src="https://johnson2heng.github.io/three.js-demo/lib/js/libs/dat.gui.min.js"></script>
<script> var renderer; function initRender() { renderer = new THREE.WebGLRenderer({antialias:true}); renderer.setSize(window.innerWidth, window.innerHeight); document.body.appendChild(renderer.domElement); } var camera; function initCamera() { camera = new THREE.PerspectiveCamera(45, window.innerWidth/window.innerHeight, 1, 10000); camera.position.set(0, 0, 100); } var scene; function initScene() { scene = new THREE.Scene(); } var light; function initLight() { scene.add(new THREE.AmbientLight(0x404040)); light = new THREE.DirectionalLight(0xffffff); light.position.set(1,1,1); scene.add(light); } function initModel() { var shape = new THREE.ShapeGeometry(drawShape()); var material = new THREE.MeshPhongMaterial({color:0xff00ff}); material.side = THREE.DoubleSide;//设置成两面都可见 var mesh = new THREE.Mesh(shape,material); scene.add(mesh); /*此方法是创建两种纹理的方法 * var shape = new THREE.ShapeGeometry(drawShape()); var mesh = createMesh(shape); scene.add(mesh); * */ } //初始化性能插件 var stats; function initStats() { stats = new Stats(); document.body.appendChild(stats.dom); } //用户交互插件 鼠标左键按住旋转，右键按住平移，滚轮缩放 var controls; function initControls() { controls = new THREE.OrbitControls( camera, renderer.domElement ); // 如果使用animate方法时，将此函数删除 //controls.addEventListener( 'change', render ); // 使动画循环使用时阻尼或自转 意思是否有惯性 controls.enableDamping = true; //动态阻尼系数 就是鼠标拖拽旋转灵敏度 //controls.dampingFactor = 0.25; //是否可以缩放 controls.enableZoom = true; //是否自动旋转 controls.autoRotate = false; //设置相机距离原点的最远距离 controls.minDistance = 20; //设置相机距离原点的最远距离 controls.maxDistance = 160; //是否开启右键拖拽 controls.enablePan = true; } //生成gui设置配置项 var gui,spGroup,tubeMesh; function initGui() { //声明一个保存需求修改的相关数据的对象 gui = { numberOfPoints:5, segments:64, radius:1, radiusSegments:8, closed:false, points: [], newPoints:function () { //生成一些随机点放置到数组当中 var points = []; for (var i = 0; i < gui.numberOfPoints; i++) { var randomX = -20 + Math.round(Math.random() * 50); var randomY = -15 + Math.round(Math.random() * 40); var randomZ = -20 + Math.round(Math.random() * 40); points.push(new THREE.Vector3(randomX, randomY, randomZ)); } gui.points = points; gui.redraw(); }, redraw:function () { //清楚掉场景中原来的模型对象 scene.remove(spGroup); scene.remove(tubeMesh); //重新绘制模型 generatePoints(gui.points, gui.segments, gui.radius, gui.radiusSegments, gui.closed); } }; var datGui = new dat.GUI(); //将设置属性添加到gui当中，gui.add(对象，属性，最小值，最大值） datGui.add(gui, 'newPoints'); datGui.add(gui, 'numberOfPoints', 2, 15).step(1).onChange(gui.newPoints); datGui.add(gui, 'segments', 0, 200).step(1).onChange(gui.redraw); datGui.add(gui, 'radius', 0, 10).onChange(gui.redraw); datGui.add(gui, 'radiusSegments', 0, 100).step(1).onChange(gui.redraw); datGui.add(gui, 'closed').onChange(gui.redraw); gui.newPoints(); } //通过配置项绘制出几何体 function generatePoints(points, segments, radius, radiusSegments, closed) { spGroup = new THREE.Object3D(); //赋值spGroup存储模型点的3d对象 var material = new THREE.MeshBasicMaterial({color: 0xff0000, transparent: false}); //声明一个红色普通纹理 //将所有的顶点创建出球形存储到spGroup内 points.forEach(function (point) { var spGeom = new THREE.SphereGeometry(0.2); var spMesh = new THREE.Mesh(spGeom, material); spMesh.position.copy(point); spGroup.add(spMesh); }); // 将spGroup对象添加到场景当中 scene.add(spGroup); // THREE.CatmullRomCurve3方法可以将一组顶点生成一条平滑的曲线 var tubeGeometry = new THREE.TubeGeometry(new THREE.CatmullRomCurve3(points), segments, radius, radiusSegments, closed); //将模型对象赋值给tubeMesh并添加到场景当中 tubeMesh = createMesh(tubeGeometry); scene.add(tubeMesh); } function createMesh(geom) { // 创建两个纹理 //创建一个透明纹理 var meshMaterial = new THREE.MeshBasicMaterial({color: 0x00ff00, transparent: true, opacity: 0.3}); //创建一个线框纹理 var wireFrameMat = new THREE.MeshBasicMaterial(); wireFrameMat.wireframe = true; // 使用纹理和几何体创建模型 var mesh = THREE.SceneUtils.createMultiMaterialObject(geom, [meshMaterial, wireFrameMat]); return mesh; } function render() { renderer.render( scene, camera ); } //窗口变动触发的函数 function onWindowResize() { camera.aspect = window.innerWidth / window.innerHeight; camera.updateProjectionMatrix(); render(); renderer.setSize( window.innerWidth, window.innerHeight ); } function animate() { //更新控制器 controls.update(); render(); //更新性能插件 stats.update(); requestAnimationFrame(animate); } function draw() { initRender(); initScene(); initCamera(); initLight(); //initModel(); initControls(); initStats(); initGui(); animate(); window.onresize = onWindowResize; } </script>
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